What is dissolved oxygen?
Dissolved oxygen (DO) is the amount of oxygen that is present in water. It is an important measure of water quality as it indicates a water body’s ability to support aquatic life. Water bodies receive oxygen from the atmosphere and from aquatic plants.
How to measure dissolved oxygen in water?
There are different methods to measure dissolved oxygen in water. Some of the common ones are:
- Iodometric method – This is a chemical analysis method that involves adding reagents to a water sample and titrating it with a standard solution of sodium thiosulfate.
- Membrane electrode method – This is an electrochemical method that uses a probe with a membrane that allows oxygen to diffuse through and generate an electric current proportional to the oxygen concentration.
- Optical probe method – This is an optical method that uses a probe with a fluorescent dye that changes its intensity or lifetime depending on the oxygen level.
What factors affect the dissolved oxygen in water?
There are many factors that affect the dissolved oxygen in water. Some of the common ones are:
- Temperature – Oxygen dissolves less in warmer water than in colder water. This is because warmer water molecules move faster and take up more space, leaving less room for oxygen molecules to fit in.
- Water flow speed – Water that is moving or turbulent tends to have more dissolved oxygen than still or stagnant water. This is because moving water mixes with air and exposes more surface area for oxygen exchange.
- Salinity – Oxygen dissolves less in saltier water than in fresher water. This is because saltier water has more ions that compete with oxygen molecules for space in the water.
- Organism respiration – Aquatic organisms such as fish, plants, algae, and bacteria use oxygen for respiration and produce carbon dioxide as a waste product. This reduces the amount of dissolved oxygen available for other organisms.
What is the dissolved oxygen level in industrial area?
Dissolved oxygen (DO) is the amount of oxygen that is dissolved in water. It is an important indicator of water quality and affects the growth and survival of aquatic organisms.
The dissolved oxygen level in industrial area depends on various factors, such as:
The type and amount of organic waste that is discharged into water by industries. Organic waste can cause oxygen demand, which means it consumes oxygen when it is decomposed by bacteria.
The temperature and pressure of water. Higher temperature and lower pressure, reduce the solubility of oxygen in water.
The aeration and mixing of water. More aeration and mixing increase the contact between water and air, which enhances the transfer of oxygen into water.
According to some sources, most industries will use water that contains only a small amount of dissolved oxygen, usually less than 2 ppm (parts per million), to prevent corrosion and damage to their equipment. However, some industrial applications may require higher levels of dissolved oxygen for optimal performance.
What is an industrial dissolved oxygen level sensor?
An industrial dissolved oxygen level sensor is a device that measures the amount of oxygen that is dissolved in water for various industrial applications. It can provide continuous and real-time monitoring of dissolved oxygen levels and alert users of any changes or problems.
There are different types of industrial dissolved oxygen level sensors, such as:
- Amperometric sensors, which use an electrochemical reaction to measure the current generated by oxygen reduction at a cathode.
- Optical sensors, which use a luminescent dye that changes its fluorescence intensity or lifetime depending on the presence of oxygen molecules.
- Wireless sensors, which use a long-range wireless mesh network to transmit data from a high-resolution DO probe to remote modems and gateways.
What unit is dissolved oxygen meter?
A dissolved oxygen meter is a device that measures the amount of gaseous oxygen dissolved in a water sample. The most common units used when measuring dissolved oxygen are mg/L (milligrams per liter) or % saturation (percentage of the maximum amount of oxygen that can be dissolved at a given temperature and pressure).
What is dissolved oxygen unit conversion?
Dissolved oxygen unit conversion is the process of changing dissolved oxygen values from one unit to another, such as from mg/L to % saturation or vice versa. There are different formulas and tables that can be used for this purpose. The conversion depends on factors such as water temperature, salinity, barometric pressure and altitude.
How to calculate dissolved oxygen?
There are different methods to calculate dissolved oxygen depending on the context and purpose. One way is to use a dissolved oxygen sensor that measures the current produced by an electrochemical reaction between oxygen and a metal electrode.
Another way is to use a titration method that involves adding chemicals to a water sample and measuring the amount of sodium thiosulfate consumed.
The third way is to use a formula based on Henry’s law that relates the dissolved oxygen concentration to the partial pressure of oxygen, its solubility coefficient, and other factors such as temperature, salinity and pressure.